Chapter
2
Presentation Slides
Prenatal
Development and
the Newborn
Period
Outline of Chapter
Prenatal
Development
Hazards to Prenatal
Development
The Birth
Experience
The Newborn Infant
Prenatal Development
Epigenesis
The emergence of new structures and functions in the
course of development
Conception

Gametes (germ cells): Reproductive cells—egg and
sperm—that contain only half the genetic material of all
other cells in the body

Meiosis: Cell division that produces gametes
In meiosis, 23 chromosomes from mother and 23
chromosomes from father leads to conception—23 pairs
of chromosomes.

Conception: The union of an egg from the mother and a
sperm from the father; fertilization

Zygote: A fertilized egg cell
Conception, Part 2
Female Reproductive
System
Conception, Part 3
Sperm nearing the egg
Developmental Processes
Four developmental processes that transform a zygote to
embryo to fetus
Mitosis: Cell division resulting in two identical daughter cells
Cell migration: Newly formed cells move away from point of
origin
Cell differentiation: Cells start to specialize in structure and
function
Apoptosis: Genetically programmed death of cells not
required/necessary
Developmental Processes, Part 2
Time
Conception
to 2 weeks
3rd to 8th
week
9th week to
birth
Period
Description
Germinal
Begins with conception and lasts until the
zygote becomes implanted in the uterine
wall. Rapid cell division takes place.
Embryonic
Following implantation, major development
occurs in all the organs and systems of the
body. Development takes place through
the processes of cell division, cell
migration, cell differentiation, and cell
death, as well as hormonal influences.
Fetal
Continued development of physical
structures and rapid growth of the body.
Increasing levels of behavior, sensory
experience, and learning.
Early Development
Identical Twins
 Twins that result from the splitting in half of the zygote
 Each of the two resulting zygotes have exactly same set of
genes
Fraternal Twins
 Twins that result when two eggs happen to release in
fallopian tubes at the same time
 Fertilized by two different sperm
 Fraternal twins have only half their genes in common
Early Development, Part 2
Neural tube: A groove formed in the top layer of
differentiated cells in the embryo that eventually becomes the
brain and spinal cord
Amniotic sac: A transparent, fluid-filled membrane that
surrounds and protects the fetus
Placenta: A support organ for the fetus that permits the
exchange of materials carried in the bloodstreams of the fetus
and mother
Umbilical cord: A tube containing the blood vessels
connecting the fetus and placenta
Fetal Behavior
Movement
 Fetal movement starts 5–6 weeks after conception
 Emergence of hiccups, swallowing
 Movement of limbs, fingers
 Respiratory readiness for breathing independently after
birth
Behavioral Cycles
 Rest–activity cycles; less activity in latter half of prenatal
period
 Circadian rhythm apparent
 REM during active sleep
Fetal Experience
Sight—minimal
Touch—contact
with parts of the
body; grasping
umbilical cord,
rubbing face,
sucking thumb
Taste—can detect
flavors in the
amniotic fluid
Smell—amniotic
fluid takes on
odor from what
the mother eats
Hearing—
responds to
various sounds
from at least 6
months
Fetal Learning
Habituation
A simple form of learning that
involves a decrease in
response to repeated or
continued stimulation
Dishabituation
The introduction of a new
stimulus rekindles interest
following habituation to a
repeated stimulus.
Hazards to Prenatal Development
Critical Period
When a particular type of
development growth
(in body or behavior)
must happen if it is to
happen
Sensitive Period
When a certain type of
development is most
likely, although it may
still happen later
Miscarriage
15% of U.S.
clinically recognized
pregnancies end in
miscarriage.
At least 25% to
possibly as high
as 50% of women
experience at least
one miscarriage.
Hazards to Prenatal Development, Part 2
Cigarettes
Slow fetal
development, low
birth weight, possible
links to SIDS
Alcohol
Fetal alcohol
syndrome
Environmental
Pollutants
Potential birth defects
Environmental
Hazards to
Fetus and
Newborn
Maternal factors
Age, nutrition, disease,
emotional state,
mental illness
Occupational
hazards
Automobile
exhaust;
factory
workers
Teratogens
Teratogen: A potentially harmful agent
Dose–response radiation: Potential problems depend on
how the mother is exposed to the teratogen and for how long.
The more exposure, the more at risk the fetus becomes.
Teratogens, Part 2
Teratogen
Radiation
Tobacco use by
mother
Effects
Timing
Disrupted development of central nervous system
8 to 15 weeks most
critical
Growth and developmental retardation
3 to 8 weeks most
critical
Microcephaly
3 to 38 weeks
Limb malformation, urinary tract damage
4 to 6 weeks
Tobacco use by
Low birth weight, reduction in weight by an average
father
of 2 oz.
(secondhand smoke)
Alcohol
Cocaine
Late pregnancy
Fetal alcohol syndrome
3 to 38 weeks
Fetal alcohol effect
3 to 38 weeks
Growth and developmental retardation
Craniofacial dysmorphism
3 to 38 weeks
Growth retardation, small head size
3 to 8 weeks
Premature birth, problems with placenta, low birth
weight
After 17 weeks
Attention difficulties, emotional regulation
After birth for several
years
Maternal Factors
Age
 Infant mortality rate high for teen mothers 15 years or
younger
 Women delaying pregnancies to their 30s or 40s risk
infertility
Nutrition
 General malnutrition of mother affects growth of fetal brain;
later cognitive impairments
 Spina bifida, neural tube defects
Maternal Factors, Part 2
Disease
 Rubella
 STIs can damage CNS of fetus
 Infections, such as influenza may lead to schizophrenia
 Zika virus – microcephaly
Maternal Emotional State
 High maternal stress leads to increased stress hormone
levels
 Could lead to behavior problems in children who were
prenatally exposed to high levels of stress hormones
Potential Results of Hazards
Sudden infant death syndrome, or SIDS—when an
infant 1 year of age or less dies suddenly and
unexpectedly with no cause
Fetal alcohol spectrum disorder, or FASD—when a
mother’s alcohol consumption during pregnancy
affects the fetus; can include facial deformities,
mental retardation, attention problems, hyperactivity,
and other defects
Fetal alcohol effects, or FAE—when an infant has
some but not all effects of FASD. Roughly 1 in 1000
infants born in the United States has FAE.
The Birth Experience





Birth of baby after 38 weeks of conception
Uterine muscles contract initiating birth
Baby in normal head-down position
Mother experiences pain
Baby experiences squeezing
• Reduces overall size of fetus’s large head
• Plates of skull overlap during birth
• Stimulates hormone production
• Forces amniotic fluid out of lungs
The Birth Experience, Part 2
Diversity of Childbirth Practices
 Childbirth practices vary across cultures.
 All cultures pursue dual goals:
• Survival and health of mother and baby
• Social integration of baby
 Cesarean (C-section): Surgical delivery of baby when
birth complications arise
 Doula: Individuals trained to assist women in terms of
emotional and physical comfort during labor and delivery
The Newborn Infant
 A healthy baby interacts with environment right away
 Explores and learns about new environment
 Exploration influenced by baby’s state of arousal
State of Arousal
State: Level of arousal and engagement
ranges from deep sleep to intense activity.
State of Arousal, Part 2
Sleep
 Newborns sleep twice as much as adults.
 Total sleep time declines regularly throughout childhood
and more slowly throughout life.
 Rapid eye movement (REM) sleep: Active sleep state,
characterized by quick, jerky eye movements under closed
eyelids
• Associated with dreaming in adults
 Non-REM sleep: Quiet or deep sleep state characterized
by absence of motor activity or eye movements
• More regular, slower brain waves, breathing, and heart
rate
State of Arousal, Part 3
State of Arousal, Part 4
Crying
 Infants cry to get attention of caregivers.
 Some reasons for crying include illness, pain, and hunger.
 Crying is normal behavior.
 Peaks around 6–8 weeks of age, and decreases around
3–4 months of age
 Soothing: Consoling crying baby
• Swaddling: A soothing technique, used in many
cultures; involves wrapping baby tightly in cloths or a
blanket
State of Arousal, Part 5
Response to Distress
 A study found that quick response to crying results in less
crying several months later.
 Another study found that ignoring crying during the first 9
weeks reduced crying during the next 9 weeks.
Colic: Excessive, inconsolable crying by a young infant for no
apparent reason
Negative Outcomes at Birth
Infant Mortality
 Death during the first year after birth
 In the United States, in 2015 there were 5.87 deaths per
1000 births.
Low Birth Weight (LBW)
 Average newborn 7 ½ pounds
 LBW – less than 5 ½ pounds
 Premature (preterm) babies – born at 37 weeks after
conception; small for gestational age
 LBW babies – high level of medical complications; high
rates of neurosensory deficits, frequent illnesses, lower IQ
scores
Overcoming Low Birth Weight
Best way to help low birth weight infants—
physical contact; social interaction
Cuddle
Caress
Carry
Negative Outcomes at Birth, Part 2
Multiple Risk Models
 Effects of cumulative and multiple risks affects normal
functioning in child
 Range from attachment to language development to wellbeing
Poverty as a Developmental Hazard
 Multiple risks strongly related to lower SES
Resilience: When an infant develops successfully, even with
hazards such as low birth weight, poverty, or other teratogens